diff options
Diffstat (limited to 'fs/eventpoll.c')
| -rw-r--r-- | fs/eventpoll.c | 56 |
1 files changed, 53 insertions, 3 deletions
diff --git a/fs/eventpoll.c b/fs/eventpoll.c index 557d5b614fae..ae228ec54e94 100644 --- a/fs/eventpoll.c +++ b/fs/eventpoll.c @@ -105,6 +105,8 @@ /* Maximum msec timeout value storeable in a long int */ #define EP_MAX_MSTIMEO min(1000ULL * MAX_SCHEDULE_TIMEOUT / HZ, (LONG_MAX - 999ULL) / HZ) +#define EP_MAX_EVENTS (INT_MAX / sizeof(struct epoll_event)) + struct epoll_filefd { struct file *file; @@ -497,7 +499,7 @@ void eventpoll_release_file(struct file *file) */ asmlinkage long sys_epoll_create(int size) { - int error, fd; + int error, fd = -1; struct eventpoll *ep; struct inode *inode; struct file *file; @@ -640,7 +642,6 @@ eexit_1: return error; } -#define MAX_EVENTS (INT_MAX / sizeof(struct epoll_event)) /* * Implement the event wait interface for the eventpoll file. It is the kernel @@ -657,7 +658,7 @@ asmlinkage long sys_epoll_wait(int epfd, struct epoll_event __user *events, current, epfd, events, maxevents, timeout)); /* The maximum number of event must be greater than zero */ - if (maxevents <= 0 || maxevents > MAX_EVENTS) + if (maxevents <= 0 || maxevents > EP_MAX_EVENTS) return -EINVAL; /* Verify that the area passed by the user is writeable */ @@ -699,6 +700,55 @@ eexit_1: } +#ifdef TIF_RESTORE_SIGMASK + +/* + * Implement the event wait interface for the eventpoll file. It is the kernel + * part of the user space epoll_pwait(2). + */ +asmlinkage long sys_epoll_pwait(int epfd, struct epoll_event __user *events, + int maxevents, int timeout, const sigset_t __user *sigmask, + size_t sigsetsize) +{ + int error; + sigset_t ksigmask, sigsaved; + + /* + * If the caller wants a certain signal mask to be set during the wait, + * we apply it here. + */ + if (sigmask) { + if (sigsetsize != sizeof(sigset_t)) + return -EINVAL; + if (copy_from_user(&ksigmask, sigmask, sizeof(ksigmask))) + return -EFAULT; + sigdelsetmask(&ksigmask, sigmask(SIGKILL) | sigmask(SIGSTOP)); + sigprocmask(SIG_SETMASK, &ksigmask, &sigsaved); + } + + error = sys_epoll_wait(epfd, events, maxevents, timeout); + + /* + * If we changed the signal mask, we need to restore the original one. + * In case we've got a signal while waiting, we do not restore the + * signal mask yet, and we allow do_signal() to deliver the signal on + * the way back to userspace, before the signal mask is restored. + */ + if (sigmask) { + if (error == -EINTR) { + memcpy(¤t->saved_sigmask, &sigsaved, + sizeof(sigsaved)); + set_thread_flag(TIF_RESTORE_SIGMASK); + } else + sigprocmask(SIG_SETMASK, &sigsaved, NULL); + } + + return error; +} + +#endif /* #ifdef TIF_RESTORE_SIGMASK */ + + /* * Creates the file descriptor to be used by the epoll interface. */ |